Folding machine



7 Feb. 5, 1946- ca. VACHON FOLDING MACHINE Filed June 15, 1944 2 Sheets-Sheet 1 Patented Feb. 5, 1946 UNITED STATES PATENT OFFICE FOLDING MACHINE Lionel G. Vachon, Groveland, Mass, assignor to 7 Boston Machine Works Company, Lynn, Mass,

a corporation of Massachusetts Application June 15, 1944, Serial No. 540,518

8 Claims This invention relates to machines for doubling back the margins of'a preshaped piece .of flexible sheet material to form a finished edge or edges thereon. The doubled-back portion, or the area against which it is to be laid, is preferably first cemented so that when it, is pressed against the face of the piece after being doubled back, it will be held fast. For example, certainshoei parts may be made in this manner, for ornamental purposes or otherwise, by doubling back the margin of a piece of soft split leather or equivalent flexible sheet material which has been previously cut to shape. A thin stiffening element of suitable material such as stiffpaper may be cemented to the blank before the margins are doubled back.

The margins will in such case be bent'back about the edges of the stiffening element and will be cemented to the exposed face thereof.

It is an object of the invention to provide a mechanism of simple but. effective structure adapted to perform the doubling-back operation and to press the resulting hem firmly while the cement on the cemented areas takes an initial set. Various other advantageous features 3 of structure will be apparent from the following description of certain embodiments of the invention illustrated in the accompanying drawings, of which Figure 1 is a perspective view of a blank for a rectangular article, having a stiffening element thereon.

Figure 2 is a perspective view of the finished article resulting from the blank shown in Figurel.

Figure 3 is a perspective view of a finished article of a different contour.

Figure 4 is a perspective view of a finished article of circular shape.

Figure 5 is a perspective view of a folding machine embodying the invention.

Figure 6 is a plan view of the machine with the top plate removed, showing certain parts in section.

Figure 7 is a vertical sectional view of the machine on the line 'l--'l of Figure 5.

Figures 8, 9 and 10 are fragmentary sectional views similar to Figure '7 but showing the working parts in difierent positions of operation.

Figure 11 is a fragmentary sectional View of a modified form of the invention.

Figure 12 is a fragmentary perspective view of a set of folder elements adapted to form the article shown in Figure4.

The machine illustrated in Figure 5 comprises a base or support which, for use, is preferably secured to-a bench or table (not shown). The base is provided with a shallow central recess 22 within which is loosely fitted a platen 24 the function of which is hereinafter explained. Mounted on the base 20 is a frame 26 having a central aperture approximately registering with the recess 22. This aperture forms a cavity which is shaped to receive, the work. The machine illustrated in Figure 5 is adapted to operate on blanks such as the one shown in Figure 1 from which the rectangular article shownin Figure 2 is made. Hence the recess 22, the platen 24 and the aperture in the frame 26 are all of similar rectangular shape.

The blank shown in Figure 1 may consist'of a piece of thin split leather 30 having its grain or finished face down. A stiffener 32 is cemented to the reverse face of the leather piece, the stiffener being cut to the size and shape of the finished piece shown in Figure 2. The margins 34 0f the blank 30 project beyond the edges of the stiffener 32 and are trimmed as at 36 so that they will not overlap when doubled back as in Figure 2.

Mounted on the frame 26 are'guide members 40 which serve to guide a group of slides or folder members 42, 44, 46, 48 and also to support a cover plate so which is secured thereon. The cover plate 50 has a central aperture which has the same size and shape as the aperture in the frame 26 and is directly above the latter so that it adds to the depth of the work-receiving cavity. The guide members 40 and cover plate 50 form passages in which are slidably fitted the four folder members. The folder members present toward the cavity respective edge portions 52, 54, 56 and 58 which are movable inwardly to project into the cavity from the sides thereof, as indicated in Figure 9. These edge portions are beveled at their respective ends to permit maxi-' mum penetration of all into the cavity. The folder members are preferably operated simultaneosuly by any suitable mechanism for the purpose. As shown, an actuator forthe member 42 is provided in the form of a finger Bil which is rockable about a shaft 62 to press against a pusher 64 which bears against the outer edge of the member 42 and is confined between guides 65, the guiding edges of which are parallel 'to the guideway of member 42. The folder members 44 and 46, which are adjacentto the member 42 at opposite sides of the path thereof, are moved inwardly toward each other in response to inward movement of the member 42. As indicated in Figure 6, this is done by means of cam edges 10 and I2 on the member 42 which engage respectively cam edges I4 and I6 on the adjacent members 44 and 46. These cam edges are all preferably inclined at angles of 45 to the directions of movement of the folder members, and the mode of operation thereof is evident from Figure 6. In like manner, inward movement of members44 and 46 results in inward movement of the member 48. V This is brought about by cam edges I8 and 89 on the members 44 and 46, respectively, which engage cam edges 82 and 84, respectively,

on the member 48. Thus when the folder mem j,

ber 42 is pushed inward, it drives the other three members inward so that each of the four folder members then protrudes into the cavity as indicated in Figures 9 and 10. The inwardmove-.

here, the latter are retracted by the spring 99.

The platen 24 may then be further raised to eject the finished work from the cavity as indicated in dotted lines in Figure 10.

ment of the member 48 is against the tension of a retracting spring 99, the ends of which are anchored to the member 48 and the frame-'29 respectively. When the member 42 is released, therefore, the spring retracts the member 48 which in tum retracts the other three folder members through the interengagement of the cam edges hereinbefore described, as is evident from Figure 6. V

For effective operation of the finger I59, it may bemounted on a hub 92 which turns on the shaft 62. An operating lever '94, provided with a handle 96, projects from the hub 92 and provides effective mechanical advantage. The ends of the shaft are secured in suitable blocks 98 at the'rear of the base 29. As shown in Figure 5, the lever 94 is arranged so that it can be swung forward and down across the work-receiving cavity and can be swung upward and backward toimpart inward movement of the folder members. The lever 94 carries a pusher plate I99 which has a shape similar to, and is slightly smaller than, the work-receiving cavity in the frame 25 and cover plate 59 and is arranged to enter the cavity when the lever is swung forward and down.

The operation of the device is as follows. When the operating lever 94 is in an intermediate position such as is shown in Figure 5 or Figure 7, the pusher I 99 is clear of the cavity and the folder members are retracted so that the cavity is ready to receive a piece of work. A blank is placed on the cover plate over the cavity; In order to facilitate proper centering, any suitable gaging means can be employed. As shown in Figure 5, a gage plate I92 having a centralaperture shaped to receive a blank 39 in flat condition is mounted on the cover plate 59. The edges around the aperture center the blank over the cavity as indicated in Figure 7'. Just before the blank'is put in position over the cavity, the margins 34 are preferably coated with fresh cement.

The lever 94 is then swung down so that the pusher plate I99 engages the blank and forces the body portion thereof and its stiffener 32 to the bottom of the cavity as in Figure 8. This causes the sides of the cavity to bend the margins 34 of the blank up out of the plane of the blank. The lever 94 is then swung upward to withdraw the pusher plate I99 from the cavity. In order gins 34 back against the body of the blank. The

In some cases it may be desired to operate on a blank which is not provided with a stiffening member. For example the work may consist of blanks I29 cut from soft, flexible leather or the like, and nothing more. In order to prevent buckling'of suchblanks and to make sure that the doubling back will be on definitely predetermined'lines of fold, the pusher I22 (Figure 11) is'provided with a ridge I24 running around its contour and projecting toward the work. The ridge is made sharp enough to indent and crease the work as at I26 but notto cut-or injure it when the lever 94 is swung down to push the work into the cavity. *The inward movement of the folder members causes the margins I39 to fold back along the crease line I26 and the platen 24 is then elevated to press the resulting hem fiat and smooth.

The mechanism illustrated in Figure 5 can be used to operate on blanks having quadrilateral shapes other than rectangles. For example, the blanks may have side edges which are concave, as in Figure 3, or are convex or otherwise. In each case, the cavity and the associated parts of the mechanism are shaped correspondingly and the margins are beveled at the corners of the quadrilateral so that there is no overlapping of marginal portions when they are doubled back as at I32 and I34.

If circular work is desired, as in Figure 4, or

'work of other shapes having no definite corners,

an annular margin I36 will necessarily wrinkle or gather when doubled back. To make a smooth job, it is necessary to present to such work a continuous folding edge. Hence the folder members may be made as indicated in Figure 12. Each of the folder members I49, I42, I44, I46 presents an arcuate folding edge the ends of which are cut away above, as at I59 or below as at I52, to provide overlapping portions which form a virtually continuous folding surface which contracts against the upstanding margin of the work when the folder members are moved inward into the cavity.

I claim:

, 1. In a device for doubling back the margins of a piece of flexible sheet material to form a peripheral hem, means for bending said margins up out of the plane of said piece, means for folding back the bent-up margins against the face of the piece, and a rockable lever operatively connected to both said mean and rockable in one direction to cause the marginsof the work to be bent up and rockable in the other direction to cause the bent-up margins to be folded back.

2. A device for doubling back the margin of a piece of sheet material of predetermined contour to form a h'em thereon, comprising a support having a shaped cavity therein to receive a piece of sheet maerial, pushing means movable to press said piece into said cavity,- a plurality of slide members movable inwardly to engage the margins of said piece, and a reciprocable member movable in one direction to operate aid pushing means to move against the work and in the reverse direction to cause said slide members to move inwardly.

3. A device for doubling back the margin of a piece of sheet material of predetermined contour to form a hem thereon, comprising a sup port having a shaped cavity therein to receive a piece of sheet material, a lever rockably mounted on said support, a pusher mounted on said lever and movable therewith to press the work into said cavity and to withdraw therefrom, a plurality of slide members movable on said support in the plane thereof into said cavity, and means on said lever operating to move said slide members into said cavity as the pusher is withdrawn from the cavity.

4. A device of the class described, comprising a horizontal support with a cavity therein shaped to receive the work, a group of four folder elements surrounding the cavity slidable on said support in a horizontal plane, means for moving one of said elements inward to project into said cavity, and means responsive to inward movement of said one element to cause the other three elements to move inward simultaneously therewith, said last-mentioned means comprising interengaging cam faces on each said element and the elements contiguous thereto.

5. A device of the class described, comprising a horizontal support having a cavity therein shaped to receive the work, a group of four folder elements horizontally slidable on said support to project into said cavity from the sides thereof, means operable to impart inward movement to one of said elements, interengaging cam faces on said one element and the two elements adjacent thereto arranged to cause said adjacent elements to move toward each other in response to inward movement of said one element, and interengaging cam faces on said adjacent elements and the element opposite to said one element arranged to cause said opposite element to move toward said one element in response to movement of said elements toward each other.

6. In a device for doubling back, the margins of a piece of flexible sheet material of which the perimeter has continuous convex curvature to form aperipheral hem, folding means comprising a plurality of pairs of horizontal flat members slidable in a common plane toward one another, each said member presenting an arcuate edge to the opposite member, the end portions of each said edge vertically overlapping end portions of the edges of the members adjacent thereto.

7. A device for doubling back the margins of a piece of flexible sheet material of predetermined contour to form a peripheral hem thereon, comprising a horizontal support having a cavity therein shaped to receive the work, means movable vertically to push the work into said cavity and to indent the work to form lines of fold, and means slidable on said support to donble back along said lines the margins of the piece against the face thereof. 7 8. In a device for doubling back the margin of a piece of flexible sheet material to form a peripheral hem, a horizontal support member having a shaped aperture corresponding to the contour of the finished work piece, a plurality of slides below said support presenting edges in approximate registry with the contour of the aperture, each said edge having a downward facing shoulder, means for pushing a work piece through said aperture to cause the marginal portions to bend up and the edges of the piece to engage said shoulders, and means for advancing said slides inward to fold back said margins.

LIONEL G. VACHON. 

